Press with adjustable stroke

ABSTRACT

A press for making parts from material comprising a die plate having first and second passages extending completely therethrough. One end of each of the passages defines a die. The die plate has first and second passage sections which intersect the first and second passages, respectively. The passage sections open at different locations on the periphery of the die plate. Appropriate tooling including the above-mentioned dies are provided for forming first and second parts from the material. The first and second parts are separately removed from the die plate by moving them through the first and second passage sections, respectively.

United States Patent 1191 1111 3,919,909

Scott Nov. 18, 1975 PRESS WITH ADJUSTABLE STROKE 3,568,554 3/1971Wiechec 83/623 x [75] Inventor: Eldred D. Scott, Tustin, Calif.

Primary Examiner-J. M. Meister [73] Asslgnee: pNreclslon salesCorporatlon, Reno Attorney, Agent, or FirmGordon L. Peterson [22] Filed:Dec. 9, 1974 [57] ABSTRACT [21] Appl. N0.: 531,146 A press for makingparts from material comprising a die plate having first and secondpassages extending Related Apphcatlon Data completely therethrough. Oneend of each of the pas- [62] 2"?" f 402290- 1973 sages defines a die.The die plate has first and second 6 passage sections which intersectthe first and second passages, respectively. The passage sections openat 7 l -l l O 0 7 5 7Q gg/ 2 9 2 different locations on the Periphery ofthe die Plate. l I t Cl 2 B26F 1/02 Appropriate tooling including theabove-mentioned {58] Fn id 2 628 dies are provided for forming first andsecond parts 0 are 83/596 1 6 from the material. The first and secondparts are separately removed from the die plate by moving themReferences Cited gzlrecililgh the first and second passage sectlons,respec- UNITED STATES PATENTS 0 509.854 1 1/1893 Sawyer 83/530 8 Clams13 Drawmg Flgures US. Patent Nov. 18, 1975 Sheet10f4 3,919,909

U.S. Patent Nov. 18,1975 Sheet 2of4 3,919,909

US. Patent Nov. 18, 1975 Sheet30f4 3,919,909

US. Patent Nov. 18, 1975 Sheet4of4 3,919,909

PRESS WITH ADJUSTABLE STROKE This is a division of application Ser. No.402,290 filed Oct. 1, 1973, now US. Pat. No. 3,863,534.

BACKGROUND OF THE INVENTION One application of a stamping press is inthe manufacture of memory cores from tape such as a ferrite tape. Eachcore is formed by a suitable set of tooling which blanks out the corefrom the tape leaving an opening in the tape. The tooling also forms anaperture in the core.

After the core is made, it must be removed from the press and.transferred to a collection point. One way of doing this is to put thecore back into the opening in the tape as shown by way of example in theRiggi US. Pat. No. 3,6l0,082. The core is then moved out of the press asthe tape is indexed through the press. One problem with this method isthat putting the core back into the tape tends to deform the core, andthis has an adverse effect upon it.

Another way of getting the core out of the press is to blow it into anadjacent chute as shown for example in Wiechec U.S. Pat. No. 3,568,554.In actual practice, a core press may have many sets of tooling so that,for each operation of the press, many cores are formed. It is necessaryor desirable to separately collect the cores formed by each set oftooling so that, if one set of tooling is making unacceptable cores,these unacceptable cores will be automatically segregated from theacceptable cores. The type of chute collection shown in the Wiechecpatent makes separate collection of cores from each set of toolingdifficult or impossible.

SUMMARY OF THE INVENTION The present invention provides a presspossessing many novel features, one of which is the solution of the coreremoval problem discussed above. The present invention employs a noveldie plate having passage sections for removal and separate collection ofthe cores formed by the press. In addition, the die plate includes aportion of the tooling utilized in making the cores and forms a guidefor another portion of such tooling.

More specifically, the die palte may have first and second passagesextending completely therethrough with one end of each of the passagesdefining a core die. The die plate also has first and second passagesections intersecting the first and second passages at first and secondintersections, respectively. The intersections are intermediate the endsof the first and second passages. The passage sections extend todifferent loca tions on the periphery of the die plate and thus performcore removal and separation functions.

The tooling means utilized to make the cores includes the core dies. Thetooling means also must position the finished cores at theabove-mentioned intersections so that the cores can be removed from thepress.

The tooling means can take different forms. How ever, it may include aplurality of core or OD. punches cooperable with the core dies to blankout the cores form the tape. Each of the core punches has a recesstherein defining an aperture die. The tooling means also includesaperture of TD. punches receivable in the pasages, respectively, of thedie plate and cooperable with the aperture to form the apertures in thecores.

Another feature of the die plate is that it guides the aperture punches.Ostensibly this function is easy to implement; however, several factorsrelating to core manufacture make it most difficult. Specifically,memory cores are extremely small, typically being of the order of 0.020inch outside diameter'0.0l5 inch inside diameter, and 0.006 inch thick.In addition, near perfect concentricity between the inner and outercircular peripheries of the core is absolutely essential. To assureproper concentricity, the passage through the die plate must be ofconstant diameter and not be stepped. However, if the passage is ofconstant diameter and if the die plate is to guide the aperture punch,then the aperture punch must be stepped. Unfortunately, stepped punchesof very small diameter are extremely difficult to make.

With the present invention, a stepped bore having the necessaryconcentricity is obtained by first forming a cylindrical bore completelythrough the die plate and then inserting an accurately formed sleeveinto one end of the passage. The sleeve provides diameter reduction andthe necessary concentricity and serves to guide the aperture punch.

For a press of this type, it is essential that the stroke of the toolingbe adjustable. The press is preferably cam driven and, accordingly, itis necessary that the adjustment be made without upsetting the timingrelationship between the cam and cam follower. With the presentinvention this is advantageously accomplished by providing an armmounted on the supporting structure of the press for pivotal movementabout a pivot axis. A cam follower is carried by the arm and engaged bythe cam so that the cam can pivot the arm about the pivot axis. Thetooling to be driven by this cam is carried by a platen. Variable lengthmeans drivingly couple the arm and the platen so that the cam can drivethe platen. The length of the variable length means can be changed toalter the stroke of the platen and the tooling without pivoting the armor altering the driving relationship between the cam and the camfollower.

It is desirable to employ two identical cams to drive one of the platensof the press. Two cams are desirable so that a direct driving force canbe applied to both ends of the platen. This, however, creates theproblem of how to make accurate identical adjustments of the motionderivable from both cams. With the present invention, this isaccomplished by employing a yoke and mounting the yoke on a plate whichin turn is drivingly coupled to the platen. By adjusting the angularposition of the yoke about its pivot axis relative to the plate, thepositions of both of the cam followers relative to the plate can beaccurately and simultaneously adjusted to thereby make an adjustment inthe stroke of the platen.

A press of the type to which the present invention is directed must havea stock feeding apparatus for indexing the stock or material through thepress. It may be come necessary to adjust the feed rate of the stockfeeding mechanism. Although prior art mechanisms provide this adjustmentfeature, it is necessary to shut down the press and the feedingmechanism to make the adjustment. One feature of this invention is thatthis adjustment can be made without shutting down the press or the stockfeeding mechanism.

The feeding mechanism can advantageously include a drive roll and anidler roll, both of which are rotatably mounted on suitable supportingstructure. A drive lever is mounted for pivotal movement in bothdirections about a pivotal axis. The drive lever is coupled to the driveroll through a one-way clutch so that the drive lever can rotate thedrive roll in only one direction. The

3 length of stroke of the drive lever is variable to thereby vary thefeed rate.

To allow for variation in the length of the stroke of the drive leverwithout interfering with the drive mechanism for the drive lever, thelever can advantageously be driven in one direction by resilient means.In a preferred embodiment, the adjustable means includes an eccentricand the drive lever is driven into engagement with the eccentric by theresilient means.

The invention can best be understood by reference to the followingdescription taken in connection with the accompanying illustrativedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. lA-lE are somewhat simplified,fragmentary, elevational views partially in section of one set oftooling showing the sequence of operations in making a core.

FIG. 2 is a top plan view of a press constructed in accordance with theteachings of this invention.

FIG. 3 is a front elevational view of the press.

FIG. 4 is an enlarged elevational view partially in section of a portionof the press shown in FIG. 3 illustrating, among other things, thetooling and the platens.

FIG. 5 is an enlarged fragmentary view partially in section takengenerally along lines 55 of FIG. 3 and illustrating a portion of themechanism for driving the core punch platen.

FIG. 6 is a fragmentary sectional view taken generally along lines 6-6of FIG. 5.

FIG. 7 is an enlarged fragmentary sectional view taken generally alonglines 7-7 of FIG. 3 and illustrating the die plate and the means forseparately collecting the cores made by the press.

FIG. 8 is an enlarged fragmentary view partially in section illustratingthe driving mechanism for the aperture punch platen.

FIG. 9' is an enlarged sectional view taken generally along line 99 ofFIG. 3 and illustrating the stock feeding mechanism. 9

DESCRIPTION OF THE PREFERRED EMBODIMENTS The Tooling and Die Plate Oneexample of the work operations which can be advantageously carried outwith the present invention is illustrated in FIGS. lA-lE. Generally FIG.1A shows a core punch 11, a die plate 13, and an aperture punch 15.Ferrite tape 17 is interposed between the core punch 11 and the dieplate 13. The ferrite tape 17 is supplied in a thin elongated strip andis of the type suitable for the manufacture of memory cores. Althoughthis invention includes many features particularly adapted to themanufacture of memory cores, it is not so limited, and the tooling shownin FIG. 1A can be utilized to stamp parts from any relatively thinmaterial including strip stock and sheet material.

The core punch 11 is tubular and has a cylindrical axial bore extendingtherethrough and opening at an annular working face 21 of the corepunch. The end of the bore 19 adjacent the working face 21 defines anaperture die 23. A stationary ejector 25 extends completely through thebore 19 in the position of the core punch 11 shown in FIG. 1A.

The die plate 13 includes a plate-like body 27 having a plurality ofcylindrical bores 29 (only one being shown in FIG. 1A) extending betweenthe opposed 4 faces of the body. The die plate 13 includes a pluralityof die buttons 31, one being fixed within each of the bores 29 (FIGS. 1Aand 7). Each of the die buttons 31 has a cylindrical axial bore 33extending between the faces of the die plate 13 with the end of the bore33 adjacent the tape 17 defining a cylindrical core die 35. The core die35 is coaxial with the core punch 11 and is sized to receive the corepunch therein. An insert in the form of an accurately constructed sleeve37 is suitably ridigly affixed within the end of the bore 33 remote fromthe core die 35. The die button 31 and the sleeve 37 are preferablyconstructed of hard, wearresistant material such as carbide.

The sleeve 37 has a cylindrical passage therein concentric with thecylindrical core die 35 and of smaller diameter. The sleeve 37 and theportion of the bore 33 which does not contain the sleeve cooperate todefine a passage through the die plate 13.

The aperture punch 15 has a cylindrical shank 39 which is slidablyreceived in and guided by the sleeve 37. The shank 39 terminates in acircular working face 41.

As best shown in FIG. 7, the die plate 13 has a plurality ofnon-intersecting passage sections 43, one being provided for each of thedie buttons 31. Each of the passage sections 43 is vertical andterminates at a different location on the periphery of the die plate 13.In the embodiment illustrated, the passage sections 43 extend completelythrough the die plate from one end to the other. Also, the passagesections 43 have vertically extending axes. As shown in FIG. 1A, thepassage section 43 includes a passage portion in the body 27 and apassage portion in the die button 31. The passage section 43 intersectsthe bore 33 intermediate the core die 35 and the sleeve 37.

The die plate 13 may include any number of the die buttons 31. Ofcourse, one core punch 11 and one aperture punch 15 is provided for eachof the die buttons 31. One of the die buttons 31 with the associatedcore punch 11 and the aperture punch 15 forms one complete set oftooling for forming a memory core. In the embodiment illustrated, eachset of tooling is identical.

In operation of the tooling, the die plate 13 remains stationary and thecore punch 11 and aperture punch 15 reciprocate according to apredetermined program, and the ferrite tape 17 is appropriately indexed.The first step in the operation of the tooling is to advance the corepunch 1 1 and the aperture punch 15 to the position shown in FIG. 1B.This causes the core punch 11 to enter the core die 35 thereby blankingout a core 45 from the tape 17 and placing the core in the core die 35.The advancing movement of the aperture punch 15 serves a prepositioningfunction to position the punch 15 for the next operation.

Secondly, the core punch 11 is held stationary and the aperture punch 15is advanced as shown in FIG. 1C, into the aperture die 23. This removesa slug 47 from the core 45 and forms an aperture in the core. The core45 is accurately formed with the inner and outer peripheries beingcircular and concentric.

Next, the aperture punch 15 is withdrawn and the core punch l l isfurther advanced as shown in FIG. 1D. This causes the core punch 1 l toeject the core 45 from the core die 35 and into the intersection of thepassage section 43 and the bore 33. The aperture punch 15 withdraws soas not to hinder this ejection movement.

The aperture punch 15 is further withdrawn and the core punch 11 iscompletely withdrawn from the core die 35 as shown in FIG. 1E. If thecore 45 is retained on the aperture punch it will be stripped off whenit contacts the sleeve 37.

The core 45 then moves through the passage section 43 and a verticalconduit 49 (FIG. 7) coupled thereto to a container 51. In the embodimentillustrated, the core 45 falls through the passage section 43 under theinfluence of gravity. One of the containers 51 is provided for each ofthe conduits 49. Thus, the cores 45 made from each set of tooling areseparately collected in separate containers.

Vacuum or positive air pressure may be provided to assist movement ofthe cores 45 to the containers 51. Pressure greater than atmospheric ispreferred because a vacuum in the passage sections 43 tends to suck theslugs 47 into the passage sections. Air pressure can be supplied to thepassage sections 43 by an air manifold 52 (FIG. 4).

The slug 47 formed in the operation illustrated in FIG. It: tends toremain within the aperture die 23. However, the core punch 1 1 iswithdrawn until the slug 47 contacts the end of the ejector 25 wherebythe slug is ejected from the aperture die. The slugs 47 canadvantageously be collected in a manner described more fully hereinbelowwith reference to FIG. 4.

It will be noted that the position of FIG. IE is identical to theposition of FIG. 1A. With the tooling in this position, the tape 17 isappropriately indexed and the above-described operation of the toolingis repeated.

FIGS. 29 show a press 53 for operating the core punch 11 and aperturepunch 15 in the manner shown in FIGS. 1A-1E. Although the press 53 isparticularly adapted for this purpose, it should be understood that manyof its features are applicable to the operation of other tooling indifferent operational sequences. Conversely, the functions illustratedin FIGS. 1A-1E can be carried out with presses of differentconstruction.

SLUG REMOVAL FIG. 4 shows the core punches 11 and the aperture punches15 in the same position as in FIGS. 1A and 1E. A collector 55 having acavity 57 extends into the path of all of the core punches 1 1 (FIG. 4).The collector 55 has one pair of aligned apertures 59 in the oppositewalls thereof for each of the core punches 11 with each of such pairbeing adapted to receive one of the core punches. The collector 55 islocated so that the working faces 21 of the core punches 11 are withinthe cavity 55 when the slugs 47 are ejected from the associated aperturedie 23. Thus, the slugs 47 enter the cavity 55 and fall under theinfluence of gravity and, if desired, with the assistance of vacuumpressure to a receptacle (not shown). Vacuum pressure may be applied tothe cavity 57 via a conduit 59a (FIGS. 2 and 4).

FIG. 4 also shows one way of mounting the ejectors 25. In the embodimentillustrated, each of the ejectors 25 is in the form of an elongated wirewhich, in the position shown in FIG. 4, projects completely through theassociated core punch 11. The ejectors 25 must be sufficiently stiff soas not to buckle in ejecting the slugs 47. The core punches 11 providesome stability for the ejectors 25. The righthand end (as viewed in FIG.4) of the ejectors 25 is received within the grooves 60 formed in a wiresupport block 61. A frame 62 sur rounds the block 61 and set screws 63in the frame engage the ejectors 25 and retain them in their respectivegrooves 60. The set screws 63 permit the effective lengths of theejectors 25 to be adjusted. The ejectors 6 engage a backup plate 64which is mounted at the right side (as viewed in FIG. 4) of the block61. Of course, other ejector mounting means could be used.

THE CORE PUNCH DRIVING MECHANISM As shown in FIGS. 2 and 3, the press 53has a base 65 on which the various components are supported. The base 65is horizontal in normal operation of the press. The ejector supportblock 61 is mounted on the base 65 by a bracket 67 (FIGS. 3 and 4).

The core punches 11 (FIG. 4) are mounted on a core punch platen 69(FIGS. 2-4) by a punch retainer 71 (FIG. 4). The core punches 11 passthrough bores in the punch retainer 71 and are affixed to the punchretainer by an adhesive such as an Epoxy adhesive.

The core punch platen 69 lies in a vertical plane and is suitablyaffixed to four spaced, parallel, horizontal shafts 73. The shafts 73are supported for horizontal reciprocating movement by four bearings 75,respectively. The bearings 75 are in turn suitably mounted on a mainplate 115 (FIGS. 2-4), which in turn are mounted on the base 65 bybrackets 117 as described more fully hereinbelow. Accordingly, the corepunches 11 and the core punch platen 69 are mounted for reciprocationalong a horizontal path relative to the base 65.

A plate 77 (FIGS. 2, 3, 5 and 6) is affixed by screws 79 to the ends ofthe shafts 73 remote from the platen 69. In the embodiment illustrated,the plate 77 is in a vertical plane and parallel to the core punchplaten 69.

A lever in the form of a yoke 81 having spaced arms 83 (FIG. 5) ispivotally mounted on the plate 77 in any suitable manner such as by pins85 for pivotal movement about a horizontal pivotal axis which isparallel to the plane of the plate 77 and which extends transversely tothe axes of the shafts 73. Springs 87 (FIGS. 5 and 6) are affixed to theyoke 81 and the plate 77 urge the yoke clockwise toward the plate 77 asviewed in FIG. 6. An adjusting screw 89 is carried by the end of theyoke 81 remote from the pivot axis of the yoke and has an end portion 91adapted to bear against the plate 77. By turning of the adjusting screw89, the angular position of the yoke 81 about its pivot axis relative tothe plate 77 can be easily manually adjusted.

Two identical cam followers 93 are rotatably mounted on the arms 83 forrotational movement about aligned, horizontal pivot axes which areparallel to the pivot axis of the yoke 81. The cam followers 93 aredriven by two identical cams 95. The cams 95 are mounted on a rotatableshaft 97 (FIG. 2) which in turn is suitably rotatably mounted forrotation above the base 65. The shaft 97 is driven by a timing pulley 99which is adapted to be driven by a motor and drive train (not shown).The shaft 97 can also be manually rotated by a handwheel 101 (FIG. 2).

The cam followers 93 are maintained in engagement with their respectivecams 95 by springs 103 (FIGS. 2, 3, 5 and 6) which are mounted on aspring actuating lever 105 (FIG. 3). The lever 105 is pivotally mountedon a shaft 107 which in turn is mounted on the base 65. The angularpositionof the lever 105 about its pivot axis can be adjusted by a screw109 which is threaded into the lower face of the base 65 and which bearsagainst the spring actuating lever.

The springs 103 project upwardly from the base 65 along oppositevertical edges of the plate 77. The springs 103 adjacent their free endsengage spring retainers 111 mounted on the plate 77. Thus, each of thesprings 103 is flexed or bent between the spring actuating lever 105 andthe associated spring retainer 111. The amount of tension or flexure ineach of the springs 103 can be adjusted by turning the screw 109.

In operation, rotation of the cams 95 imparts movement to the corepunches 11 as described with reference to FIGS. 1A-1E through the camfollowers 93, the yoke 81, the plate 77, the shafts 73, the core punchplaten 69, and the punch retainer 71. The springs 103 act against thespring retainers 11 1 to maintain the cam followers 93 in engagementwith the associated earns 95. Thus, the cams 95 drive the core punches11 to the right as viewed in FIG. 4 and the springs 103 drive the corepunches to the left as viewed in FIG. 4.

One advantage of the dual cams 95 is that the driving force from thecams is imparted to appropriately spaced locations on the plate 77 toprevent any tendency of the plate and the shafts 73 to tilt. As shown inFIG. 5, the pins 85 which pivotally attach the yoke 81 to the plate 77are located in line with two of the shafts 73. The end portion 91 of theadjusting nut 89 also bears against the plate 77 along a line drawnbetween two of the shafts 73. Thus, an even pushing action on the plate77 and the four shafts 73 is obtained.

The length of stroke of the core punches 11 is established by thecontour of the identical carns 95. However, the ends of the stroke canbe adjusted by turning the adjustment screw 89. For example, if theadjustment screw 89 is turned to pivot the yoke 81 counterclockwise asviewed in FIG. 6, the plate 77 and hence the core punches 11 are movedto the right relative to the cam 95, i.e., retracted. Upon subsequentrotation of the cams 95, the length of the stroke of the core punches 11will be unaltered, but the core punches 11 will not advance as far intothe core dies 35. The springs 87 maintain the end portion 91 inengagement with the plate 77.

One feature of this stroke adjustment mechanism is that limited pivotalmovement of the yoke 81 about its pivot axis in response to turning ofthe adjusting screw 89 will not significantly alter the relationshipbetween the cam 95 and the cam follower 93. Stated differently, turningof the adjusting screw 89 with the press 53 not operating will notsignificantly change the point of engagement of the cams 95 and the camfollowers 93. If

these points of contact were altered when making the adjustment, thetiming relationship established by the cams 95 relative to other pressmovements described hereinbelow would be altered. Adjustment of the yoke81 with the adjusting screw 89 does very slightly alter the position ofthe cam follower 93 along the surface of the cam 95. However, theadjustments to the stroke of the core punches 11 are so small for thevery small cores 45 that it causes no adverse effect on the timing thevarious press functions.

Another advantage of this construction is that the turning of theadjustment screw 89 automatically and simultaneously makes accurate,identical adjustments for both of the cams 95.

THE MOUNTING OF THE DIE PLATE The die plate 13 is affixed by screws 1 13(FIG. 7) to a main plate 115 (FIGS. 2 and 4). The air manifold 52 isalso suitably affixed to the main plate 115. The main plate 115 issuitably affixed to the base 65 and is stationary with respect thereto.For example, the opposite vertical edges of the main plate 115 may bereceived and retained in slots 116 (FIG. 2) formed in upstanding 8brackets 117 (FIG. 2) which in turn are bolted to the base 65 by bolts118.

THE APERTURE PUNCH DRIVE MECHANISM Although the aperture punches 15 canbe retained by the punch retainer 21 in any suitable manner, as shown inFIG. 4, the aperture punches 15 are mounted on an aperture punch platen1 19 by a punch retainer 121 and a block 123. The block 123 is mountedon the platen 119 by fasteners 124. The punches 15 project throughopenings in the punch retainer 121, and the heads of the punches 15 areconfined between the retainer 121 and the block 123. The punch retainer121 is receivable in a cavity 125 in the main plate 115.

The aperture punch platen 119 is mounted for horizontal reciprocation bya plurality of horizontal parallel shafts 127 which are affixed to themain plate 115 and which project through bearing blocks and bearings 129affixed to the platen 119. The shafts 127 are parallel to the shafts 73,and therefore the movements of the platens 119 and 69 are parallel. Theaperture punch platen 119 is resiliently urged to the left as viewed inFIG. 4 by a plurality of springs 131 acting between the main plate 115and the aperture punch platen. In this manner, the aperture punches 115are mounted for reciprocating movement as described hereinabove inconnection with FIGS. lA-lE.

The aperture punch platen 119 is driven by the mechanism shown in FIG.8. Specifically, a cam 133 is mounted on the shaft 97 for rotation withthe shaft and with the cam 95. A lever 135 is mounted by a screw 137 ona bracket 139 for pivotal movement about a horizontal pivotal axisextending transverse to the direction of movement of the aperture punchplaten 119. The bracket 139 is affixed to the base 65 in any suitablemanner such as by a plurality of screws 141. A cam follower 143 isrotatably mounted on the lever 135 intermediate the ends thereof. Aroller 145 is 'rotatably mounted on the outer end of the lever 135 andis engagable with a push rod 147 which is mounted at the upper end ofthe bracket 139 for horizontal reciprocating movement parallel to theshafts 127. A spring 149 urges the push rod 147 to the left as viewed inFIG. 8 and into tight engagement which the roller 145. The end of thepush rod 147 remote from the roller 145 engages as adjustment screw 151which is screwed into the block 123 (FIG. 4).

In operation, rotation of the cam 133 imparts movement to the camfollower 143 which pivots the lever 135 about the screw 137. The roller145 pivots with the lever 135 to exert a pushing force on the push rod147 which is transmitted to the aperture punches 15 through theadjustment screw 151, the block 123, and the aperture punch platen 119.The cam 133 drives the aperture punches 15 to the right as viewed inFIG. 4, i.e., advances the aperture punches and the springs 131 move theaperture punches 15 to the left, i.e., retract the aperture punches. Thesprings 131 and 149 assure that the cam follower 143 will remain inrolling contact with the cam 133.

The length of the stroke of the aperture punches 15 is fixed by the cam133. However, by turning the adjustment screw 151, the starting andstopping locations for the stroke of the aperture punches 15 can beadjusted. The adjustment screw 151 constitutes variable length means forvarying the position of the aperture punch platen 1 19 relative to thecam 133. For example, by turning the adjustment screw 151 outwardly toincrease its effective length the aperture punch platen 119 is moved tothe right as viewed in FIG. 1 whereby the stroke of the aperture punchesis correspondingly adjusted. Turning of the adjustment screw 151 doesnot result in pivotal movement of the lever 135. Accordingly, turning ofthe adjustment screw 151 does not change the location of the region ofcontact between the cam 133 and the cam follower 143.

THE STOCK FEEDING MECHANISM I The press 53 has a stock feeding mechanism153 (FIGS. 3 and 9) for indexing the tape 17 in increments through thepress. Although various stock feeding mechanisms could be employed, thestock feeding mechanism 153 is preferred because the rate of stockindexing can be adjusted while the press 53 is running.

The stock feeding mechanism 153 is driven by a cam 155 (FIGS. 2 and 3),a cam follower 157, a lever 159, and a link 161. The lever 159 ispivotally mounted by a pin 163 on a mounting bracket 165 which in turnis suitably mounted on the base 65. The cam follower 157 is rotatablymounted on the upper end of the lever 159, and the link 161 is pivotallyconnected to the lower end of the lever.

The stock feeding mechanism 153 includes end plates 167 and 169 suitablyinterconnected to form a frams (E16. 9). An idler roll 171 is mounted ona shaft 173 by bearings 175. The shaft 173 extends between the endplates 167 and 169. The idler roll 171 is free wheeling.

A drive roll 177 is mounted closely adjacent the idler roll 171 so thatthe tape 17 can be tightly gripped between the rolls. The shaft 173extends through oversized slots 179 in the end plates 167 and 169 and isbiased to the right as viewed in FIG. 9 by two springs 151. The biasingaction of the springs 181 enables the rolls 171 and 177 to frictionallygrip the tape 17 therebetween. A microswitch 133 is operated by theshaft 173 in response to movements of the shaft 173 in the slots 179.This actuation of the microswitch 183 can be utilized, for example, toprovide an appropriate indication of the absence of the tape 17 from thestock feeding mechanism 153.

The drive roll 177 is mounted on a rotatable shaft 183 by bearings 187.The shaft 155 extends between the end plates 167 and 169. A one-wayclutch 189 is also mounted on the shaft 35 for rotation with the shaft.When the clutch 1139 is rotated counterclockwise as viewed in FIG. 3, itfrictionally engages an annular sur face 155 on the drive roll 177 torotate the latter. When the shaft 155 rotates in the opposite direction,the clutch 159 does not drive the drive roll 177.

One end of the shaft 185 protrudes beyond the end plate 167 and has alever, which may be in the form of a crank 191, suitably affixed theretoby a set screw 193. The crank 191 has an arm 195 which is pivotallyjoined to one end of the link 161 (FIG. 3) and another ann 197. A spring199 (FIG. 3) is coupled to the arm 197 and to the base 65 to resilientlybias the crank 191 in a counterc1ockwise direction as viewed in FIG. 3.An abutment in the form of an eccentric 2111 is mounted on a shaft 2113for rotational movement therewith. The shaft 2113 is mounted on the endplates 167 and 169 and retained on the plates by a collar 2115. Thespring 199 urges the arm 197 counterclockwise as viewed in F IG. 3 intoengagement with the eccentric 2111. It also urges the link 161 to theleft and this tends to pivot the lever 19 159 clockwise to move the camfollower 157 toward and/or into engagement with the cam 155.

In operation of the stock feeding mechanism 153, rotation of the cam 155pivots the lever 159 counterclockwise thereby pivoting the crank 191clockwise. The one way clutch 159 (FIG. 9) does not transmit thisclockwise motion to the drive roll 177 and, accordingly the drive roll177 does not rotate as the crank 191 is pivoted clockwise.

Ultimately, the cam 155 terminates the clockwise motion to the crank 191and allows the crank to pivot in the counterclockwise direction. Whenthis occurs, the spring 199 pivots the crank 191 counterclockwise andthe one-way clutch 189 transmits this motion to the drive roll 177 torotate the latter. Because the tape 17 is frictionally gripped betweenthe drive roll 177 and the idler roll 171, rotation of the drive roll bythe spring 199 pulls an increment of the tape 17 through the press 53.The counterclockwise movement of the crank 191 continues until the arm197 is stopped by engagement with the eccentric 2111. Thus the cam 155cocks the crank 191 and the spring 199 provides the tape-feeding motion.

-To adjust the length of the tape 17 which is indexed through the press53 for each counterclockwise motion of the crank 191, the eccentric 201is adjusted by manually turning the shaft 203 and then locking the shaftin the new angular position with an appropriate lock, such as a diallock, (not shown). The angular position of the eccentric 2111 can beadjusted while the press 5.3 is running. Thus, to increase the rate offeed the eccentric 2111 is turned to increase the arc of thecounterclockwise motion of the crank 191.

If the eccentric 201 is rotated to decrease the rate of feed, the lever159 is pivoted through the link 1161 to move the cam follower 157 awayfrom the cam 155. Thus, for some angular positions on the eccentric 201,the cam follower 157 will not be in continuous contact with the cam 155during a full revolution of the cam.

OVERALL OPERATION OF THE PRESS 53 The operation of the varioussubassemblies of the press 53 and of the tooling are set forth above andwill not be repeated in detail. The cams and 133 are programmed toprovide movement of the core punches 11 and aperture punches 15 asdescribed in connection with FIGS. 1A-1E. Of course, these programs canbe varied depending upon the requirements of the parts being produced.Similarly, the cam 155 is appropriately contoured so that it will feedthe tape 17 each time the tooling is in the position shown in FIG. 1E.

The tape 17 is pulled down through the press 53. As shown in FIG. 3, atape support plate 2117 is pivotally mounted on hinges 2.119. A roller211 is rotatably mounted on the opposite end of the plate 2117. The tape17 is supported and guided by the plate 267 and the roller 211.

Both of the platens 69 and 119 and the die plate 13 are coupled to themain plate 115. Accordingly, the platens 69 and 119, the die plate 13,the piate 77, the yoke 81, and the adjustment screw 151 are removablefrom the base 65 as a unit for repair, maintenance, and inspection bysimply pulling the main plate upwardly out of the slots 116.

Although exemplary embodiments of the invention have been shown anddescribed, many changes, modifications and substitutions may be made bythose skilled 1 1 in the art without necessarily departing from thespirit and scope of this invention.

I claim:

1. A press for performing a work operation on material comprising:

a supporting structure;

a platen adapted to carry a first tool;

first and second shafts connected to said platen;

bearing means for supporting said shafts on the supporting structure forreciprocatory movement whereby the platen and the first tool can bereciprocated;

a connecting member connected to said first and second shafts;

a yoke having first and second arms, said arms being spaced apart;

means for mounting said yoke on said connecting member for pivotalmovement about a pivot axis; first and second cam followers carried bythe first and second arms, respectively;

first and second rotatable cams mounted on the supporting structure andcooperable with said first and second cam followers to drive saidconnecting member whereby the first tool is driven;

means for adjusting the angular position of the yoke about said pivotaxis relative to said connecting member whereby the positions of both ofsaid cam followers relative to said connecting member can be accuratelyand simultaneously adjusted to thereby make an adjustment in the strokeof the first tool; and

means for holding a second tool in a position to cooperate with thefirst tool whereby the tools can perform a work operation on saidmaterial.

2. A press as defined in claim 1 wherein said connecting member and saidplaten are on opposite sides of said bearing means and said means forholding said second toolbeing generally intermediate said connectingmember and said first tool.

3. A press as defined in claim 1 wherein said means for holding a secondtool includes a second platen mounted on the supporting sturcture formovement relative thereto, said press also including a lever mounted onsaid supporting structure for pivotal movement about a second pivotaxis, a third can follower carried by said arm, a third can rotatablymounted on the supporting structure and engageable with the third camfollower to drive said third cam follower and to pivot said lever aboutsaid second pivot axis, and variable length means for drivingly couplingsaid arm and second platen whereby said third cam can drive the secondplaten, the length of said'variable length means being 12 variable tochange the stroke of the second platen and the second tool withoutsignificantly altering the driving relationship between the third camand the third cam follower.

4. A press as defined in claim 1 wherein said connecting member and saidplaten are generally parallel and said pivot axis is generallytransverse to said shafts, said adjusting means including a rotatablethreaded member cooperable with said yoke and said connecting member toadjust the angular position of the yoke about said pivot axis relativeto said plate.

5. A press as defined in claim 1 including means for driving said secondtool along a path, said driving means including at least one driveelement extending through the space between said arms of said yoke.

6. A press as defined in claim 1 wherein said cams drive the first toolaway from the material, said press including spring means for drivingthe first tool toward the material whereby the spring means provides theforce for performing said work operation.

7. A press for performing a work operation on material comprising:

a supporting structure;

an arm mounted on said supporting structure for pivotal movement about apivot axis;

a cam follower carried by said arm;

a cam rotatably mounted on said supporting structure and engageable withsaid cam follower to drive said cam follower to thereby pivot said armabout said pivot axis;

a platen adapted to carry a first tool;

means for mounting said platen on said supporting structure forreciprocatory movement;

variable length means for drivingly coupling said arm and said platenwhereby said cam can drive the platen, the length of said last mentionedmeans being variable to change the, reciprocatory movement of the platenand the tool without altering the driving relationship between the camand the cam follower; and

means for holding a second tool in a position to cooperate with thefirst tool whereby the tools can perform a work operation on thematerial.

' .8. A press as defined in claim 7 wherein said reciprocatory movementincludes a first stroke in which the first tool is moved away from thematerial and a second stroke in which the first tool is moved toward thematerial, said cam driving said first tool on said first stroke, andspring means for driving said first tool on said second stroke.

1. A press for performing a work operation on material comprising: asupporting structure; a platen adapted to carry a first tool; first Andsecond shafts connected to said platen; bearing means for supportingsaid shafts on the supporting structure for reciprocatory movementwhereby the platen and the first tool can be reciprocated; a connectingmember connected to said first and second shafts; a yoke having firstand second arms, said arms being spaced apart; means for mounting saidyoke on said connecting member for pivotal movement about a pivot axis;first and second cam followers carried by the first and second arms,respectively; first and second rotatable cams mounted on the supportingstructure and cooperable with said first and second cam followers todrive said connecting member whereby the first tool is driven; means foradjusting the angular position of the yoke about said pivot axisrelative to said connecting member whereby the positions of both of saidcam followers relative to said connecting member can be accurately andsimultaneously adjusted to thereby make an adjustment in the stroke ofthe first tool; and means for holding a second tool in a position tocooperate with the first tool whereby the tools can perform a workoperation on said material.
 2. A press as defined in claim 1 whereinsaid connecting member and said platen are on opposite sides of saidbearing means and said means for holding said second tool beinggenerally intermediate said connecting member and said first tool.
 3. Apress as defined in claim 1 wherein said means for holding a second toolincludes a second platen mounted on the supporting sturcture formovement relative thereto, said press also including a lever mounted onsaid supporting structure for pivotal movement about a second pivotaxis, a third can follower carried by said arm, a third can rotatablymounted on the supporting structure and engageable with the third camfollower to drive said third cam follower and to pivot said lever aboutsaid second pivot axis, and variable length means for drivingly couplingsaid arm and second platen whereby said third cam can drive the secondplaten, the length of said variable length means being variable tochange the stroke of the second platen and the second tool withoutsignificantly altering the driving relationship between the third camand the third cam follower.
 4. A press as defined in claim 1 whereinsaid connecting member and said platen are generally parallel and saidpivot axis is generally transverse to said shafts, said adjusting meansincluding a rotatable threaded member cooperable with said yoke and saidconnecting member to adjust the angular position of the yoke about saidpivot axis relative to said plate.
 5. A press as defined in claim 1including means for driving said second tool along a path, said drivingmeans including at least one drive element extending through the spacebetween said arms of said yoke.
 6. A press as defined in claim 1 whereinsaid cams drive the first tool away from the material, said pressincluding spring means for driving the first tool toward the materialwhereby the spring means provides the force for performing said workoperation.
 7. A press for performing a work operation on materialcomprising: a supporting structure; an arm mounted on said supportingstructure for pivotal movement about a pivot axis; a cam followercarried by said arm; a cam rotatably mounted on said supportingstructure and engageable with said cam follower to drive said camfollower to thereby pivot said arm about said pivot axis; a platenadapted to carry a first tool; means for mounting said platen on saidsupporting structure for reciprocatory movement; variable length meansfor drivingly coupling said arm and said platen whereby said cam candrive the platen, the length of said last mentioned means being variableto change the reciprocatory movement of the platen and the tool withoutaltering the driving relationship between the cam and the cam follower;and means for holding a second tool in a poSition to cooperate with thefirst tool whereby the tools can perform a work operation on thematerial.
 8. A press as defined in claim 7 wherein said reciprocatorymovement includes a first stroke in which the first tool is moved awayfrom the material and a second stroke in which the first tool is movedtoward the material, said cam driving said first tool on said firststroke, and spring means for driving said first tool on said secondstroke.